semple



J. B. SEMPLE.

FUSE.

APPLICATION FILED AUG-2. 191B.

Patented July 22, 1919.

UNITED STATES PATENT OFFICE.

JOHN B. SEMPLE, 0F SEWICKLEY, PENNSYLVANIA.

FUSE.

To all whom it man concern.-

Be it known tiat 1, JoIIN B. SEMPLE, residing at Sewickley, in the county of Allegheny and State of Pennsylvania, a citizen of the United States, have invented or discovered certain new and useful Improvements in Fuses, of which improvements the following is a specification.

My invention relates to the detonation of inert high explosives, and its object is to provide a detonating train of explosives of exceedingly small volume which will effect positive and certain detonation of inert high explosives.

The detonation of relatively inert high explosives, such as T. N. T., picric acid, etc., is usually effected by the detonation of a relatively sensitive explosive, such as fulminate of mercury, which may be discharged or detonated by heat, as for example by an electrically heated wire or a flame from a percussion cap. To assure detonation of an inert high explosive by an initiating explosive such as fulminate of mercury, it has been found necessary to use about one fourth of a gran'i of the latter, and in practice larger quantities are used to guard against weakening by reason of dampness or otherwise. The initiating explosive being very sensitive, its use in the quantities heretofore found necessary to effect certain detonation of inert explosive, involves a factor of danger which it is desirable to overcome, and furthermore it, must, when used in detonating fuses, be inclosed in a very strong casmg to avoid disastrous consequences should it become prematurely exploded.

My invention is predicated upon my discovery that a very small quantity of a sensi tive initiating explosive may be rendered effective to certainly accomplish the detonation of an inert high explosive by placing adjacent to the initiating explosive a small body of an explosive having to a marked degree the property of auto-acceleration, and accelerating power upon the initiating explosive.

While in its broad aspects my invention is not limited to specific explosives, I have found that an exceedingly small amount of fulminate of mercury, when accelerated by the discharge of a small body of silver acetylid, will effect the detonation of a body of tetryl, which latter in turn will detonate any quantity of T. N. T. or other inert high Specification of Letters Patent.

Patented July 22, 1919.

Application filed August 2, 1918. Serial N 0. 248,022.

explosives. For example, I have found that the necessary volume of these three successively arranged explosives, namely, silver acetylid, fulminate of mercury and tetryl, may be so small as to be contained in a bore of about five hundredths of an inch in diameter and about four tenths of an inch long. The total weight of such uantities is very much less than twentyve hundredths of a gram, which has heretofore been authoritatively stated to be the minimum amount of any explosive or explosives necessary to effect detonation of T. N. T. or picric acid.

By way of illustrating my invention, 1 have shown in the accompanying drawing a 1011 itudinal sectional view to greatly enlarge scale of a plug or casing 1 provided with a central bore in which the train of detonating explosives is arranged. At the upper end of the bore there is an igniter 2 which may be a ercussion cap of any well known or desired construction. The train of ex losives may, as already stated, con sist o a small body 3 of silver acetylid, a body 4 of fulminate of mercury, and a body 5 of tetryl. Other explosives may be used in place of those specifically mentioned. For example the accelerator or accelerating explosive body 3 may be lead azid or nitrodiazobenzeneperchlorate or other sensitive explosive having, when discharged, an accelerating power upon the initiating body 4. In place of tetryl, there may be used T. N. A. or other explosives readily detonatable by fulminate of mercury and having a large jump or reach as compared to fulminate of mercury. It has been found that a small body of the latter, even when its detonation is accelerated, does not have sufiicient jump to detonate a body of inert high explosive unless such explosive is in immediate and close contact with the fulminate of mercury. It is, accordingly, for the purpose of providing the required detonation jump that the third body 5 of inert explosive is arranged in the bore of the casing 1 adjacent to the initiating explosive. The three explosives may be arranged in immediate contact With each other or they may be separated by thin disks of paper.

The detonation train of explosives may be used in a fuse for detonating high explosives in any type of ordnance, or in fuses for other purposes. It has the manifest advantages of economy and safetyeconomy, because of the very small quantity required, and safety because of the ease with which a very small quantity of explosive may be held in a metal case without disrupting the case if premature explosion shouldoccur. When the accelerating body 3 is ignited it greatly accelerates or magnifies the detonating power of the initiating body 4 of fulminate of mercury. The latter in turn detonates the insensitive Widejump explosive 5, which in turn will detonate any amount of insensitive detonatin explosives such as T. N. T., picric acnfi etc., even through a metal seal or across a small air g I claim as my invention:

1. In a fuse for detonating high explosives a detonation train of explosives comprising successively arranged small bodies of an accelerating explosive, a sensitive initiating detonating explosive, and an inert detonating explosive having a large detonation jump as compared to that of the second-named explosive.

2. In a fuse for detonating high explosives a detonation train of explosives comprising successively arranged small bodies of an accelerating explosive, fulminate of mercury, and an inert explosive havin a substantially larger detonation jump tian fulminate of mercury.

3. In a fuse for detonating high explosives a detonation train of explosives com prising successively arranged small bodies of silver acetylid, fulminate of mercury and an inert explosive having a substantially larger detonation jump than fulminate of mercury.

4. In a fuse for detonating high explosives a detonation train of explosives comprising successively arranged small bodies of silver acetylid, fulminate of mercury and tetryl.

5. In a fuse, the combination of a body of inert high explosive, a small body of detonation initiating explosive in substantially immediate contact With said firstnamed body, and an accelerating body of explosive adjacent to said initiatlng explo sive.

6. In a fuse, the combination of a body of inert high explosive, a small body of fulminate of mercury in substantially immedi ate contact With said body, and an accelerating body of explosive adjacent to said fulminate of mercury.

In testimony whereof I have hereunto set my hand.

PAUL N. CRrroHLovv, FRANCIS J. TOMASSON.

copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents. Washington, D. 0. 

